Size Of Pieces Research Articles

Chimpanzee (Pan troglodytes) anticipation of food return: Coping with waiting time in an exchange task.

Despite controversial expectations that animals achieve reciprocal altruism, it is unclear if nonhuman species possess the necessary cognitive abilities. For reciprocal altruism, individuals must anticipate the loss of a commodity and accept a delay before some return. The authors investigated the abilities of 5 chimpanzees (Pan troglodytes) to cope with increasing waiting duration in exchange tasks. Subjects had to keep a small cookie before returning it to a human partner to obtain a larger piece. For a piece 2, 4, or 8 times the size of the small piece, 3 of the 5 subjects waited for up to 4 min. For a piece 40 times larger, 4 of the 5 subjects waited up to 8 min. At long time lag, renouncement to wait occurred earlier than predicted by subjects' general waiting capacity, suggesting that the decision to wait was based on a trade-off between reward quantity and expected costs of the waiting duration. Chimpanzees could anticipate a delayed reward at a time scale of several minutes. If this reflects a cognitive limit in chimpanzees' anticipation capacity, reciprocal altruism by keeping track of costs and benefits over extended periods may be unlikely in chimpanzees.

Effect of thinning and prescribed fire restoration treatments on woody debris and snag dynamics in a Sierran old-growth, mixed-conifer forest

Forest managers have little information of the effects of common restoration treatments, thinning and burning, on dead woody material (DWM) dynamics in fire-suppressed forests. Fine woody debris (FWD; 0.6–29.9 cm), coarse woody debris (CWD; ≥30.0 cm), and snags (≥5 cm) were inventoried and mapped in eighteen 4 ha plots before and after applying thinning (overstory, understory, and no thinning) and burning (burn and no burn) treatments. The combination of burning and thinning reduced FWD and CWD quantity and mean piece size, removed highly decayed logs, and increased small (5.0–24.9 cm) snag recruitment. In contrast, thin-only treatments produced similar results but increased FWD and did not remove many small snags. There were no differences in DWM response between the two thinning treatments. Log and snag spatial patterns prior to and following treatment were similar. These results indicate that burning in combination with thinning is more effective at reducing surface FWD and CWD, and removing small trees than are burn-only and thin-only treatments. Although large snags and logs were consumed in the burn, long-term recruitment of these habitat structures relies on managers retaining large-diameter trees. Repeated burns need to be conducted after initial restoration treatments to understand natural patterns of DWM.

Using Discrete Event Simulation to Assess Human Lifting and Assembly of Vehicle Armor

The Future Combat Systems (FCS) program goal is to develop the next generation of vehicles and networks for the Army. Eight configurations of Manned Ground Vehicles (MGV) are being designed as part of this effort. Requirements state that each MGV must weight less than 20 Tons to be C-130 transportable. To achieve this weight limitation the armor will be removed before flight. The armor will be flown in on a separate aircraft and installed at the destination. A specific challenge for the manufacturer of the MGVs is determining how best to utilize human resources in the installation process. This poster will describe the use of discrete event simulation to develop a human performance model that helps determine an optimal combination of manpower, armor panels, and installation equipment. Four different “up-armor” scenarios were simulated each with different manpower, number of armor pieces, size of armor pieces, and material handling equipment requirements.

Comparison of routine and unprepped CT colonography augmented by low fiber diet and stool tagging: a pilot study

We performed a pilot study examining the feasibility of a new unprepped CT colonography (CTC) strategy: low fiber diet and tagging (unprepped) vs. low fiber diet, tagging and a magnesium citrate cleansing preparation (prepped). Prior reports of tagging were limited in that the residual stool was neither measured and stratified by size nor did prior reports subjectively evaluate the ease of interpretation by a reader experienced in interpreting CTC examinations. Prospective randomized to unprepped n = 14 and prepped n = 14. Colonic segments were subjectively evaluated for residual stool that would potentially interfere with interpretation. Scores were given in the following categories: percentage of residual stool that was touching or nearly touching mucosa, the largest piece of retained stool, effectiveness of tagging, height of residual fluid, degree of distention, ease of interpretation, and reading time. Ease of the CT read (scale where 4 = optimal read) averaged 1.3 for the unprepped group and 2.3 for the prepped group. The mean read time averaged 17.5 min for unprepped and 17.9 min for prepped. The degree of distention (scale where 4 = well distended) averaged 3.7 for unprepped and 3.6 for prepped. Supine and prone images combined, the unprepped group had 160 segments with stool; prepped group had 58 segments. The amount of stool covering the mucosa in all segments averaged 1.6 (33%-66% coverage) in the unprepped group and 0.35 (<33% mucosal coverage) in the prepped group. The mean size of the largest piece of stool was 33.67 mm for unprepped and 4.01 mm for prepped. Percentage of tagged stool was not significantly different between the groups (range of 94-98%). The height of residual fluid averaged 8.37 mm for unprepped and 13.4 mm for prepped. Three polyps in three patients were found during optical colonoscopy (OC) in the unprepped group (5, 6, and 10 mm), none of which were prospectively detected at CTC. Three polyps in three patients were detected during OC in the prepped group (5, 10, and 15 mm), two of which were prospectively detected at CTC. Two false-positive lesions were observed at CTC in one patient in the prepped group. There was more stool in the unprepped group and while this factor did not slow down the reading time, it made the examination subjectively harder to interpret and likely caused the three polyps in this group to be missed. We conclude that a truly unprepped strategy that leaves significant residual stool, even if well tagged, is not desirable.

Effect of Test Piece Size on Rheological Behavior of Wood Composites

The effect of size and the combined effect of the size and moisture sorption of test pieces on the long term creep behavior of wood composites were studied. Small-, wide-, and semisize test pieces from each of three commercial wood composites, particleboard (PB), oriented strand board (OSB), and medium density fiberboard (MDF) were tested. Three exposure regimes, constant 20°C/65%, a single change from 20°C/65% to 20°C/85%, and cyclic changes between 20°C/30% and 20°C/90% relative humidity (RH), were used. It was found that the width of test pieces had no effect while the length had a significant effect on long term behavior of wood composites, but the effect is in contrast to that of short term modulus of rupture (MOR) which ranged from 0.06 to 0.13 for the shape parameter and from 0.09 to 0.26 for the length parameter depending on the types of wood composites. The average ratio of the relative creep ( kc ) of small-:wide-:semisize was 1.14:1.13:1.00 for PB, 1.26:1.21:1.00 for MDF, and 1.24:1.24:1.00 for...

Performance of a Fume‐Exhaust Gun System in CO2 Arc Welding

Although the incidence of pneumoconiosis has been decreasing in Japan, welders’ health hazards due to welding fume inhalation are still serious, because effective engineering methods for controlling fumes are technically difficult to implement in many welding shops. In the 6th notification of general prevention of dust hazards issued by the Japanese Ministry of Health, Labor and Welfare (2003–2007), a fume-exhaust gun system was recommended as an effective ventilation device for welding fume control. An ordinary fume-exhaust gun system consists of a welding torch with a suction hood which exhausts the air around the welding arc, a fume collector, and a flexible duct which connects the hood to the collector (Fig. 1). The ventilation is supposed to be performed effectively by means of the suction hood distributed around the periphery of the torch. The air contaminated with welding fumes is carried from the hood through the flexible duct to the fume collector where it is cleaned and then recirculated to the welding shop. Since a fume-exhaust gun requires much lower air removal than other local ventilation systems or a general ventilation system, it should be beneficial to the running cost of the ventilation. In addition, a fume-exhaust gun is superior to the other local ventilation systems in applicability. Unlike the fixed hood of a usual local exhaust ventilation system, a fumeexhaust gun has a hood which does not limit the size of the work piece and welder’s mobility because its hood is always close to the arc point and does not require laborious repositioning or adjustment. However, the gun performance will be affected by the geometry of the weld joint and the shielding gas flow rate. When the hood suction is distorted due to some welding position or excess in shielding gas, the fume plume may tend to rise away from the hood of the gun. In this study the author investigated the effects of welding position, elevation angle of weld line and flow rate of shielding gas on fume-exhaust gun performance.

Effect of processing and storage of Jameed on conjugated linoleic acid content and fat and cholesterol oxidation

The influence of Jameed processing and storage on fat and cholesterol oxidation, hydrolytic rancidity, and conjugated linoleic acid (CLA) was evaluated by determining peroxide value (PV), 7-ketocholesterol, free fatty acids content (FFAs) and total CLA. Three different sizes of Jameed pieces (ca. 50, 200 and 400 g balls) were used to investigate the influence of storage for 0, 1, 3, 5 and 7 months on the above lipid oxidation parameters. No significant ( P > 0.05 ) effect of the Jameed processing steps on lipid changes was found with the exception of the sun drying steps, that caused an increase of PV, 7-ketocholesterol and FFA contents and a decrease in CLA content. This trend was also observed during storage of Jameed at room temperature and kept exposed to light and atmospheric air. The PV values of the 50, 200 and 400 g balls after 7 months of storage were 35.3, 19.4 and 20.4 meq O 2 kg −1 of fat, that were 17, 11 and 12 times higher compared with the corresponding values of the fresh samples (1.9 meq O 2 kg −1 of fat ). The 7-ketocholesterol of the tested samples increased from about 5.7 μg g −1 to 210, 120 and 125 μg g −1 for the 50, 200 and 400 g balls, respectively. FFA content increased remarkably during storage, from about 1.3 g kg −1 at the beginning of storage to 8.6 g kg −1 of fat after 7 months with no significant ( P > 0.05 ) effect for the size of Jameed pieces on FFAs content. On the contrary, a decrease of about 43%, 26% and 26% of the original value (5.7 mg kg −1 of fat) in CLA content was found for the stored Jameed pieces of 50, 200 and 400 g, respectively.

Submucosal Endoscopy - A Novel Approach to En Bloc Endoscopic Mucosal Resection

Background: The submucosal layer is of eminent importance for polypectomy and endoscopic mucosal resection in the gastrointestinal tract. Submucosal infiltration is the critical step of tumor invasion and subsequent metastasis. A mucosal neoplastic lesion has to be stripped off the underlying muscular layer during an endoscopic resection. Herein we describe for the first time the development of submucosal endoscopy (SE), a novel and innovative method, that allows diagnostic and therapeutic endoscopy of the submucosal space (SS) in the esophagus (E). Materials and Methods: SE was performed in pigs under general anesthesia. After placing a plastic tube in the proximal E for a quick access a right-angled area was marked with a diathermic probe to define a mucosal piece for resection. After local infiltration of the submucosa with epinephrine (1:100000) a 1-2 cm transverse incision was performed with a Storz normal calibre videoendoscope (NCVE) 2-3 cm proximal and distal of these margins. Through the proximal incision we entered the SS with a flexible Storz small calibre videoendoskop and dissected the net-shaped submucosal connective tissue in a longitudinal direction with a blunt forceps. Coarse fibres and blood vessels were coagulated and severed. The lifted mucosa was subsequently separated with the NCVE and an insulated-tip needle-knife. The resected particle was retrieved with a snare. Finally the animals were euthanized and the explanted E was tested for leakages by inspection and hard filling with water. Results: Overall 15 mucosal pieces were resected. The size of the resected pieces varied from 1,6 cm × 0,9 cm to 7,4 cm × 1,7 cm. All of them could be completely resected en bloc. The mean time for resection of one mucosal piece was 36 min (median time 25 min, range 16-108 min). The endoscopic view in the SS was excellent. The blunt and diathermic dissection of the submucosal connective tissue was unproblematic. In the SS inspection of the muscularis and of the underside of the mucosa was easily accomplishable. There were no bleeding and no perforation of the muscularis. Conclusions: Diving into the SS for SE is a novel, innovative and practicable method for the dissection of mucosal neoplastic lesions. We demonstrate, that mucosal areas of various sizes could be resected en bloc without complications. The sight in the SS was surprisingly good. We speculate that the penetration of a tumor into the SS would accurately be assessed by SE. Lesions limited to the mucosa would get resected en bloc according to oncologic standards by this novel method. Human trials will show whether peritumorous inflammatory changes may impede submucosal dissection.

Layer-by-layer cutting of rocks

To describe the process of cutting of geomaterials by a two-sided wedge, a rigid-plastic model is considered taking into account the influence the wedge speed has on the cutting force, shear plane orientation, and sizes of sheared pieces.

606 温度観察による疲労特性の評価(材料と組織)

In order to evaluate the fatigue Characteristics of an aluminum alloy 2024, temperature change during the rotary bending fatigue test was measured with the infrared thermometer. As a result, temperature rose rapidly along with the growth in number of cycles, the tendency for temperature to fall gradually after it peals was obtained. Moreover, a big and small size of the test piece was prepared, and then temperature change was measured when the test was done with those specimens. From this test, influence of size on temperature was considered. In addition, temperature of test pieces that gave the stress in advance was measured by a similar method, and then influence of history of stress was investigated.

First thinning in sub-tropical eucalypt plantations grown for high-value solid-wood products: a review

SummaryThe decision to first thin a eucalypt plantation grown for high—value products must be based on the growth, wood quality and financial consequences of the decision. These factors are interrelated and at present some are difficult to quantify. This review summarises available knowledge on a range of factors influencing the decision to first thin in eucalypt plantations, with specific reference to sub-tropical eastern Australia.The most compelling reason for early thinning is to remove defective stems before they become dominant within the stand. In plantations of unimproved genetic stock, a high proportion of stems can be of inferior quality, and in these circumstances stand quality and value recovery can be greatly increased by early, possibly non-commercial, thinning. Stands of ‘intolerant’ species, such as Eucalyptus grandis, segregate into dominance classes earlier than do stands of more ‘tolerant’ species. Delaying thinning may allow defective stems to become dominant, suppressing some of the higher-quality stems which are then less able to respond to later thinning. In this regard, management options for eucalypts are generally much less flexible than for tolerant genera such as pines. This may be less important for stands of improved genetic material, which are more uniform, or for stands with a small proportion of defective stems.To maximise growth on final-crop trees, thinning should be undertaken as early as possible to take advantage of early rapid growth rates that cannot be attained later. Thinning too early, however, may reduce wood quality. The most common reason for downgrade in eucalypt plantation timber is knots. If pruning is not undertaken, delaying thinning until the lower branches die takes advantage of the excellent self-pruning behaviour of some sub-tropical species.Optimum thinning regimes are a trade-off between maximising growth on the smallest possible number of stems while fully utilising the site and minimising risk from biological and climatic factors. Maximising growth on the smallest number of stems allows critical threshold log sizes to be attained rapidly, thereby maximising the advantages from minimising time to financial returns. If thinning is too severe the site will not be fully occupied, resulting in lost production and problems such as weed growth, epicormic flushing and wind damage.The benefit or cost of early thinning depends on harvest costs, its effect on wood quality, product assortment, average piece sizes and available volumes per hectare. There are significant risks and opportunity costs associated with delaying thinning that may be greater than the perceived financial benefits—e.g. the immediate saving from not conducting a non-commercial thinning may be negated by a reduced total (net present) value recovery and lower internal rate of return over the rotation.

Mechanics of thin-film transistors and solar cells on flexible substrates

When devices are fabricated on thin foil substrates, any mismatch strain in the device structure makes the work piece curve. Any change of the radius of curvature produces a change in the size of the work piece, and thereby misalignment between individual device layers. To achieve tight tolerances, changes of curvature must be minimized throughout the fabrication process. Amorphous silicon thin-film transistors and solar cells respond differently to externally applied tensile strain. The elastic deformation of the transistor is correlated with small increase in the electron mobility. When the tensile strain reaches ∼0.34%, crack formation starts and causes an abrupt change in the transistor performance. The performance of solar cells, on the other hand, does not change for tensile strain up to ∼0.7%. At larger strain the short-circuit current, open-circuit voltage, fill factor, and the efficiency gradually decrease.

Finger trees: a simple general-purpose data structure

We introduce 2-3 finger trees, a functional representation of persistent sequences supporting access to the ends in amortized constant time, and concatenation and splitting in time logarithmic in the size of the smaller piece. Representations achieving these bounds have appeared previously, but 2-3 finger trees are much simpler, as are the operations on them. Further, by defining the split operation in a general form, we obtain a general purpose data structure that can serve as a sequence, priority queue, search tree, priority search queue and more.

Edge-reinforced random walk on a ladder

We prove that the edge-reinforced random walk on the ladder ℤ×{1,2} with initial weights a>3/4 is recurrent. The proof uses a known representation of the edge-reinforced random walk on a finite piece of the ladder as a random walk in a random environment. This environment is given by a marginal of a multicomponent Gibbsian process. A transfer operator technique and entropy estimates from statistical mechanics are used to analyze this Gibbsian process. Furthermore, we prove spatially exponentially fast decreasing bounds for normalized local times of the edge-reinforced random walk on a finite piece of the ladder, uniformly in the size of the finite piece.

Developing Optimal Commercial Thinning Prescriptions: A New Graphical Approach

Abstract We describe an alternative approach to the traditional stand-density management diagrams and stocking guides for determining optimum commercial thinning prescriptions. Predictions from a stand-growth simulator are incorporated into multiple nomograms that graphically display postthinning responses of various financial and biological response variables (mean annual increment, piece size, final harvest cost, total wood cost, and net present value). A customized ArcView GIS computer interface (ThinME) displays multiple nomograms and serves as a tool for forest managers to balance a variety of competing objectives when developing commercial thinning prescriptions. ThinME provides a means to evaluate simultaneously three key questions about commercial thinning: (1) When should thinning occur? (2) How much should be removed? and (3) When should the final harvest occur, to satisfy a given set of management objectives? North. J. Appl. For. 22(3):170 –174.

Conversion of Elongation Values for Cold-Rolled Low Carbon Steel Sheets

Abstract It is often difficult or impossible to prepare tension test pieces from flat steel products to specified standard size due to inadequate sample piece size. Hence several sizes of test pieces yielding different gage lengths are envisaged. However, the value of the total elongation beyond maximum stress in tension testing depends on the gage length due to the effect of necking. Acceptance values of elongation at fracture for flat steel products are therefore specified together with corresponding gage lengths, e.g., 50 or 80 mm (fixed gage lengths) and k So (proportional gage lengths) where k takes the value of 4.00, 5.65, 8.16, or 11.30 and k √SO is the original cross-sectional area of the test piece in mm2. Methods for converting room temperature percentage elongation at fracture obtained on various proportional and nonproportional gage lengths to other gage lengths exist for austenitic, carbon, and low alloy steels as hot-rolled, normalized, annealed, etc., but not as cold-reduced. These methods are also not valid where the gage length is greater than 25 times √SO or where the width-to-thickness ratio of the test piece is greater than twenty. This paper proposes a possible solution for cold-rolled low carbon steel sheets of thickness less than 2.0 mm, which continue to be, if not the major, one of the major raw materials in the automotive industry. The solution lies in the modification of the exponent in the Oliver formula used for flat steel products other than cold-rolled low carbon steel sheets.

Strength in concrete reinforced with recycled CFRP pieces

This paper presents strength in concrete reinforced with recycled and crushed carbon fiber reinforced plastic (CFRP) pieces. Mechanical properties such as compressive and flexural strength of CFRP reinforced concrete (CFRPRC) were evaluated and its fracture behavior was characterized. First, compressive and flexural tests of CFRPRC were conducted to investigate the effect of size and content of CFRP pieces on compressive and flexural strength and work of fracture in the flexural tests. Secondly, pull-out and peel tests were performed to estimate the adhesion strength at the interface. Finally, fracture surfaces were observed with an optical microscope and an electron probe micro analyzer to characterize fracture behavior and adhesion at the interface between CFRP and cement. Flexural strength increases and compressive strength increases slightly with increasing CFRP content. In the load-displacement curves in the flexural tests of CFRPRC specimens, large displacement is observed after maximum load. As a result, work of fracture of reinforced specimens is much higher than that of blank specimens. Good bonding at the interface due to anchoring effect was confirmed through the microscopic observation and the pull-out and peel tests. It is concluded that addition of CFRP pieces with appropriate size to concrete improves the flexural strength and work of fracture due to bridging effect.

Default Risk Sharing Between Banks and Markets: The Contribution of Collateralized Debt Obligations

This paper contributes to the economics of financial institutions risk management by exploring how loan securitization a.ects their default risk, their systematic risk, and their stock prices. In a typical CDO transaction a bank retains through a first loss piece a very high proportion of the expected default losses, and transfers only the extreme losses to other market participants. The size of the first loss piece is largely driven by the average default probability of the securitized assets. If the bank sells loans in a true sale transaction, it may use the proceeds to to expand its loan business, thereby incurring more systematic risk. We find an increase of the banks' betas, but no significant stock price e.ect around the announcement of a CDO issue. Our results suggest a role for supervisory requirements in stabilizing the financial system, related to transparency of tranche allocation, and to regulatory treatment of senior tranches.

Mesh segmentation schemes for error resilient coding of 3-D graphic models

Most existing coding techniques for three-dimensional (3-D) graphic models focus on coding efficiency. Due to irregular structure of the 3-D mesh and the use of variable length entropy codes, channel errors often propagate in the coded bitstream and severely distort the decoded model. By segmenting a 3-D graphic model (or its connected components) into small pieces, the impact of channel errors is confined to directly corrupted pieces rather than the whole mesh. The mesh segmentation schemes should be compatible with the underlying encoding techniques to achieve the low computational and coding overhead. In this research, we examine four mesh segmentation schemes, i.e., multiseed traversal, threshold traversal, morphing-based volume splitting, and content-based segmentation, and apply them to the context of error resilient mesh coding based on the constructive traversal coding technique. The advantages and shortcomings of each segmentation method are discussed. These schemes segment a mesh into pieces according to the target piece size that is determined according to the channel error rate.

Mesh segmentation schemes for error resilient coding of 3-D graphic models

Most existing coding techniques for three-dimensional (3-D) graphic models focus on coding efficiency. Due to irregular structure of the 3-D mesh and the use of variable length entropy codes, channel errors often propagate in the coded bitstream and severely distort the decoded model. By segmenting a 3-D graphic model (or its connected components) into small pieces, the impact of channel errors is confined to directly corrupted pieces rather than the whole mesh. The mesh segmentation schemes should be compatible with the underlying encoding techniques to achieve the low computational and coding overhead. In this research, we examine four mesh segmentation schemes, i.e., multiseed traversal, threshold traversal, morphing-based volume splitting, and content-based segmentation, and apply them to the context of error resilient mesh coding based on the constructive traversal coding technique. The advantages and shortcomings of each segmentation method are discussed. These schemes segment a mesh into pieces according to the target piece size that is determined according to the channel error rate.